{"id":2226168,"url":"http://patchwork.ozlabs.org/api/patches/2226168/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/bmm.hhub2sjuj4.gcc.gcc-TEST.redi.10.1.1@forge-stage.sourceware.org/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/projects/17/?format=json","name":"GNU Compiler Collection","link_name":"gcc","list_id":"gcc-patches.gcc.gnu.org","list_email":"gcc-patches@gcc.gnu.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"","list_archive_url":null,"date":"2026-04-22T10:19:29","name":"[v1,1/1] libstdc++: Add align_alloc attribute to aligned operator new","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"a7f27fc745057702803a6f189feda5dbc585fe25","submitter":{"id":93210,"url":"http://patchwork.ozlabs.org/api/people/93210/?format=json","name":"Jonathan Wakely via Sourceware Forge","email":"forge-bot+redi@forge-stage.sourceware.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/bmm.hhub2sjuj4.gcc.gcc-TEST.redi.10.1.1@forge-stage.sourceware.org/mbox/","series":[{"id":500960,"url":"http://patchwork.ozlabs.org/api/series/500960/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=500960","date":"2026-04-22T10:19:29","name":"libstdc++: Add align_alloc attribute to aligned operator new","version":1,"mbox":"http://patchwork.ozlabs.org/series/500960/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2226168/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2226168/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=38.145.34.32; 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server2.sourceware.org","From":"Jonathan Wakely via Sourceware Forge\n ","Date":"Wed, 22 Apr 2026 10:19:29 +0000","Subject":"[PATCH v1 1/1] libstdc++: Add align_alloc attribute to aligned\n operator new","To":"gcc-patches mailing list ","Message-ID":"\n ","X-Mailer":"batrachomyomachia","X-Pull-Request-Organization":"gcc","X-Pull-Request-Repository":"gcc-TEST","X-Pull-Request":"https://forge.sourceware.org/gcc/gcc-TEST/pulls/10","References":"\n ","In-Reply-To":"\n ","X-Patch-URL":"\n https://forge.sourceware.org/redi/gcc/commit/f0bfdb357d6bf4f3ea82b5e6baecd30cfed971bf","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Reply-To":"gcc-patches mailing list , redi@gcc.gnu.org","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"},"content":"From: Jonathan Wakely \n\nThe aligned versions of operator new should use the align_alloc\nattribute to help the compiler.\n\nPR c++/86878 requests that the compiler would use the attribute to warn\nabout invalid attributes, so an XFAILed test is added for that.\n\nlibstdc++-v3/ChangeLog:\n\n\t* libsupc++/new (operator new): Add attribute align_alloc(2) to\n\toverloads taking a std::align_val_t argument.\n\t* testsuite/18_support/new_aligned_warn.cc: New test.\n---\n libstdc++-v3/libsupc++/new | 6 +++---\n .../testsuite/18_support/new_aligned_warn.cc | 13 +++++++++++++\n 2 files changed, 16 insertions(+), 3 deletions(-)\n create mode 100644 libstdc++-v3/testsuite/18_support/new_aligned_warn.cc","diff":"diff --git a/libstdc++-v3/libsupc++/new b/libstdc++-v3/libsupc++/new\nindex e9a3d9b49a3e..4345030071bb 100644\n--- a/libstdc++-v3/libsupc++/new\n+++ b/libstdc++-v3/libsupc++/new\n@@ -167,7 +167,7 @@ void operator delete[](void*, const std::nothrow_t&)\n #if __cpp_aligned_new\n _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t)\n _GLIBCXX_TXN_SAFE\n- __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));\n+ __attribute__((__externally_visible__, __alloc_size__ (1), __alloc_align__ (2), __malloc__));\n _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&)\n _GLIBCXX_TXN_SAFE\n _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));\n@@ -178,10 +178,10 @@ void operator delete(void*, std::align_val_t, const std::nothrow_t&)\n _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));\n _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t)\n _GLIBCXX_TXN_SAFE\n- __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));\n+ __attribute__((__externally_visible__, __alloc_size__ (1), __alloc_align__ (2), __malloc__));\n _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&)\n _GLIBCXX_TXN_SAFE\n- _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__));\n+ _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __alloc_align__ (2), __malloc__));\n void operator delete[](void*, std::align_val_t) _GLIBCXX_TXN_SAFE\n _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__));\n void operator delete[](void*, std::align_val_t, const std::nothrow_t&)\ndiff --git a/libstdc++-v3/testsuite/18_support/new_aligned_warn.cc b/libstdc++-v3/testsuite/18_support/new_aligned_warn.cc\nnew file mode 100644\nindex 000000000000..e9d374abe317\n--- /dev/null\n+++ b/libstdc++-v3/testsuite/18_support/new_aligned_warn.cc\n@@ -0,0 +1,13 @@\n+// { dg-options \"-Wattributes\" }\n+// { dg-do compile { target c++17 } }\n+\n+#include \n+\n+int main()\n+{\n+ // PR c++/86878 has a patch to make these warn.\n+ (void) operator new(1, std::align_val_t(3)); // { dg-warning \"power of two\" \"\" { xfail *-*-* } }\n+ (void) operator new[](1, std::align_val_t(10)); // { dg-warning \"power of two\" \"\" { xfail *-*-* } }\n+ (void) operator new(1, std::align_val_t(0), std::nothrow_t()); // { dg-warning \"power of two\" \"\" { xfail *-*-* } }\n+ (void) operator new[](1, std::align_val_t(-1), std::nothrow_t()); // { dg-warning \"power of two\" \"\" { xfail *-*-* } }\n+}\n","prefixes":["v1","1/1"]}